A marine deep-towed DC resistivity survey in a methane hydrate area, Japan Sea

Goto, T.; Kasaya, Takafumi; Machiyama, Hideaki; Takagi, Ryo; Matsumoto, Ryo; Okuda, Y.; Satoh, Mikio; Watanabe, Toshiki; Seama, Nobukazu; Mikada, Hitoshi; Yukitoshi, Sanada; Kinoshita, Masataka

doi:10.1071/eg08003

Cited by 54 publications

(59 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Generally, the noise level of MERI is generated by data errors, tides, electrode spacing, altitude, and towed movement, among others. The noise-level range suggested by Goto et al (2008) is 10% -15%. Therefore, the authors suggest that static measurement and development receivers on seafloor are required to reduce noise levels.…”

Section: Resultsmentioning

confidence: 99%

“…Previous MERI experiments (Francis 1985;Von Herzen et al 1996;Goto et al 2008;Chiang et al 2011) did not check their imaging abilities with an inversion algorithm which realistically accounted for noise effect; thus, this study used conventional Wenner, PD, and DD arrays to ensure that this effect was accounted for. The synthetic Fig.…”

Section: Two-dimensional Inversionmentioning

confidence: 99%

“…To test the sensitivity of the various electrode arrays, 30 μV of Gaussian noise was added to the synthetic modeling results, based on a field experiment (Goto et al 2008;Goto 2009, personal communication). The apparent resistivities for Wenner, PD, and DD array with and without noise are shown in Figs.…”

Section: Two-dimensional Inversionmentioning

confidence: 99%

“…In contrast, the resistivity of marine sediments generally ranges from 0.8 to 1.5 ohm-m, and the resistivity of seawater (although dependent on salinity and temperature variations) is generally within the range of 0.286 to 0.33 ohm-m. Therefore, the large resistivity contrast that exists between these features may provide an excellent opportunity to image electrical resistivity anomalies beneath the seafloor (Von Herzen et al 1996;Goto et al 2008;Chiang et al 2011). However, inversion studies concerning sensitivity have not yet been completed, and past studies have been based on one-dimensional data-processing methods (Francis 1985;Von Herzen et al 1996;Goto et al 2008;Schwalenberg et al 2010), which are unable to account for lateral variations in the subseafloor structure.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Sensitivity of Deep-Towed Marine Electrical Resistivity Imaging Using Two-Dimensional Inversion: A Case Study on Methane Hydrate

Chiang¹,

Goto²,

Mikada³

et al. 2012

Terr. Atmos. Ocean. Sci.

Self Cite

View full text Add to dashboard Cite

Uncertain physical properties of methane hydrate (MH) above a bottom simulating reflector should be estimated for detecting MH-bearing formations. In contrast to general marine sediments, MH-bearing formations have a relatively high electrical resistivity. Therefore, marine electrical resistivity imaging (MERI) is a well-suited method for MH exploration. The authors conducted sensitivity testing of sub-seafloor MH exploration using a two-dimensional (2D) inversion algorithm with the Wenner, Pole-Dipole (PD) and Dipole-Dipole (DD) arrays. The results of the Wenner electrode array show the poorest resolution in comparison to the PD and DD arrays. The results of the study indicate that MERI is an effective geophysical method for exploring the sub-seafloor electrical structure and specifically for delineating resistive anomalies that may be present because of MH-bearing formations at a shallow depth beneath the seafloor.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Two-dimensional Inversionmentioning

confidence: 99%

Section: Two-dimensional Inversionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Sensitivity of Deep-Towed Marine Electrical Resistivity Imaging Using Two-Dimensional Inversion: A Case Study on Methane Hydrate

Chiang¹,

Goto²,

Mikada³

et al. 2012

Terr. Atmos. Ocean. Sci.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Since the first MTER survey with submersible passive electrode cables was carried out by Francis (1985), MTER has become an effective geophysical tool to discern sulfide deposits (Francis 1985;Von Herzen et al 1996) and methane hydrate (MH) (Goto et al 2008) due to the large contrast in electrical resistivity in comparison to most sub-seafloor sediments. However, previous studies have mostly used horizontal arrays.…”

Section: Introductionmentioning

confidence: 99%

Efficiency of a Marine Towed Electrical Resistivity Method

Chiang¹,

Goto²,

Chen³

et al. 2011

Terr. Atmos. Ocean. Sci.

Self Cite

View full text Add to dashboard Cite

In contrast to marine sediments, because of large electrical resistivity anomalies found in sulfide deposits and methane hydrates, resistivity measurements such as marine towed electrical resistivity (MTER) might be a feasible method for discovering those natural minerals. To determine the feasibility of the MTER method we examined arrays consisting of a pole electrical dipole (PED), vertical electrical dipole (VED) and horizontal electrical dipole (HED). The VED array showed a maximum difference in electric fields of 36% and 105% in the resistive and conductive models, respectively, while the PED and HED arrays yielded worse results of around 13% to 19%, respectively. The VED array showed a higher difference in electric fields than both the HED and PED arrays in the two models. Therefore, we suggest that a VED array with a large electrical current would be most conducive leading to the discovery of such minerals during MTER surveys.

show abstract

Vulcan: A deep‐towed CSEM receiver

Constable

Kannberg

Weitemeyer³

2016

Geochem Geophys Geosyst

View full text Add to dashboard Cite

We have developed a three‐axis electric field receiver designed to be towed behind a marine electromagnetic transmitter for the purpose of mapping the electrical resistivity in the upper 1000 m of seafloor geology. By careful adjustment of buoyancy and the use of real‐time monitoring of depth and altitude, we are able to deep‐tow multiple receivers on arrays up to 1200 m long within 50 m of the seafloor, thereby obtaining good coupling to geology. The rigid body of the receiver is designed to reduce noise associated with lateral motion of flexible antennas during towing, and allows the measurement of the vertical electric field component, which modeling shows to be particularly sensitive to near‐seafloor resistivity variations. The positions and orientations of the receivers are continuously measured, and realistic estimates of positioning errors can be used to build an error model for the data. During a test in the San Diego Trough, offshore California, inversions of the data were able to fit amplitude and phase of horizontal electric fields at three frequencies on three receivers to about 1% in amplitude and 1° in phase and vertical fields to about 5% in amplitude and 5° in phase. The geological target of the tests was a known cold seep and methane vent in 1000 m water depth, which inversions show to be associated with a 1 km wide resistor at a depth between 50 and 150 m below seafloor. Given the high resistivity (30 Ωm) and position within the gas hydrate stability field, we interpret this to be massive methane hydrate.

show abstract

A marine deep-towed DC resistivity survey in a methane hydrate area, Japan Sea

Cited by 54 publications

References 10 publications

Sensitivity of Deep-Towed Marine Electrical Resistivity Imaging Using Two-Dimensional Inversion: A Case Study on Methane Hydrate

Sensitivity of Deep-Towed Marine Electrical Resistivity Imaging Using Two-Dimensional Inversion: A Case Study on Methane Hydrate

Efficiency of a Marine Towed Electrical Resistivity Method

Vulcan: A deep‐towed CSEM receiver

Contact Info

Product

Resources

About